Tretinoin Capsules are a retinoid-based targeted drug used for the treatment of acute promyelocytic leukemia (APL). It exerts therapeutic effects by inducing the differentiation of leukemic cells and inhibiting their proliferation; however, strict adherence to medication administration guidelines is required to avoid risks such as embryotoxicity and differentiation syndrome.

How to Use Tretinoin Capsules

Indications and Diagnostic Confirmation

Tretinoin Capsules are indicated for APL patients confirmed to have the t(15,17) chromosomal translocation or PML/RARα fusion gene via cytogenetic or molecular testing, especially those who are resistant to or have contraindications for anthracycline-based chemotherapy.

Before medication administration, the indication must be confirmed through morphological diagnosis combined with genetic testing to avoid incorrect use in non-target populations.

Administration Regimen

Dose: The recommended dose is 22.5 mg/m², taken orally twice daily, until complete remission (CR) is achieved.

Treatment Course: After CR is achieved, continue medication for 30 days, or for a total treatment course not exceeding 90 days (whichever comes first).

Administration Method: The capsules must be taken with meals and swallowed whole; do not chew, dissolve, or open the capsules, as this may affect efficacy. If the time since a missed dose is more than 10 hours before the next scheduled dose, the missed dose can be supplemented; no supplementary dose is needed if vomiting occurs after administration.

Dosage Adjustment of Tretinoin Capsules

Adjustments Related to Adverse Reactions

Differentiation Syndrome: Occurs in approximately 26% of patients, presenting with symptoms such as fever, dyspnea, and weight gain. When symptoms appear, intravenous dexamethasone (10 mg every 12 hours) must be administered immediately, and tretinoin should be suspended until symptoms resolve.

Increased Intracranial Pressure: More common in children; dosage reduction or drug discontinuation is required, and concurrent use of drugs that may increase intracranial pressure (such as tetracyclines) should be avoided.

Hepatotoxicity: If liver enzyme levels rise more than 5 times the upper limit of normal, it is recommended to suspend medication until levels return to normal.

Impact of Drug Interactions

CYP3A Inhibitors/Inducers: Strong inhibitors (e.g., ketoconazole) may increase plasma drug concentrations, requiring close monitoring for toxicity.

Strong inducers (e.g., rifampicin) may reduce efficacy; concurrent use should be avoided.

Antifibrinolytic Drugs: Increase the risk of thrombosis; concurrent use is prohibited.

Administration of Tretinoin Capsules in Special Populations

Pregnant and Lactating Women

Contraindication in Pregnancy: Tretinoin has confirmed teratogenicity. A negative pregnancy test must be confirmed before medication administration, and dual contraceptive measures should be used during treatment and for 1 month after drug discontinuation.

Lactation: Breastfeeding is prohibited during treatment and for 1 week after the last dose.

Pediatric and Elderly Patients

Pediatric Patients: Can be used in children aged ≥1 year, but the risk of increased intracranial pressure must be closely monitored; lumbar puncture for decompression or dosage reduction may be necessary if required. Safety in children aged <1 year has not been established.

Elderly Patients: No dosage adjustment is needed compared with younger patients, but enhanced monitoring for adverse reactions is required.